Split pressure roller stations are usually employed in the case of known rotary presses. Such rotary presses include a frame, a rotor having a drive, a frame housing, supporting corner connections, a head plate, and a drive base, in which the pressure rollers are received by an upper and a lower receptacle device, wherein the upper receptacle device is attached to the head plate of the rotary press, and the lower receptacle device is attached to the drive base of the rotary press.
The two pressure rollers strive to move apart by virtue of the pressing force that arises in the pressing process. The pressure rollers are prevented from doing so by the two receptacle devices on the head piece and on the base of the rotary press, as well as by the two to four pieces of corner connections which interconnect the head piece and the base. The forces that arise in the pressing process are directly introduced into the head piece and the base by way of the rams and the receptacle devices and excite these components by way of the pressing forces to oscillate at frequencies which are in the audible range and thus lead to significant noise emissions.
For example, pressure roller stations in which the frame includes upper and lower transverse supports which are connected by vertical stays are described in U.S. Pat. No. 3,891,375. Furthermore, the pressure roller station described in U.S. Pat. No. 3,891,375 includes two pillars which are disposed between the stays and on which the pressure-roller axles of the pressure rollers are mounted in a sliding manner. The frame is mounted in the press frame so as to be pivotable about a vertical axis, in the closed position forming a component part of the press housing. The frame may be pivoted from the operating position thereof by approximately 90° to the open position, wherein the drive of the pressure rollers is uncoupled and the pressure rollers disengage from the upper ram and the lower ram, respectively. The pressure-roller axle for the upper pressure roller is connected to the upper transverse support by means of a settable spacer. The spacer serves for setting the plunging depth of the upper ram into the dies of the die disk. The pressure-roller axle for the lower pressure roller by way of a shaft is connected to a hydraulic setting unit which for the purpose of setting the tablet thickness and thus the pressing tone acts on the lower pressure roller.
It is disadvantageous that the pressing force is absorbed by the entire press frame, on account of which the configuration of the pressure roller station disclosed in U.S. Pat. No. 3,891,375 is associated with a high and costly effort in terms of material, since the frame of the rotary press and the corner connections have to be embodied so massively that the arising pressing forces can be reliably absorbed by the former. Furthermore, oscillations which may lead to noise disturbances are initiated by the force profile running through the frame. Moreover, the mounting of the pressure-roller axles for the pressure rollers on the two vertical pillars and on the frame that is pivotable in the press frame is soft and resilient such that the pressure roller station described in U.S. Pat. No. 3,891,375 is usable only for minor pressing forces.
A pressure roller station in which the upper and the lower pressure roller of the rotary press are attached to a cylindrically configured guide pillar, wherein the upper and the lower pressure roller are mutually adjustable, is described in U.S. Pat. No. 6,186,762. By way of the pressure roller station described in U.S. Pat. No. 6,186,762, the issue of noise nuisance and the dissipation of pressing force by way of the entire frame is thus solved, but new issues are created on account thereof. In the case of the pressure roller station described in U.S. Pat. No. 6,186,762, it is disadvantageous that the cylindrical guide pillar of the pressure roller station has a cylindrical closed external wall. While this is welcome in the context of the hygiene requirements that are applicable to the pharmaceutical sector, a technician who is entrusted with maintaining the components located in the interior of the guide profile or with replacing components that are in need of replacement in the case of a defect, faces the issue of having to dismantle the pressure roller station in its entirety from the rotary press. By virtue of a total weight of the pressure roller station, which is usually in the range of 500 kg, this is possible only when using lifting gear that is specially made for this purpose. On account thereof, downtime of the rotary tablet press is caused, and personnel are tied up.
It has furthermore been found that the sliding guides of the upper and lower pressure roller receptacle, as described in U.S. Pat. No. 6,186,762, have a mutual play of the components, the play being established by the manufacturing tolerances. This play is no longer capable of being corrected post assembly of the rotary tablet press.
Systems, methods, and devices for producing medicine molds which above all are used for producing tablets, gel caps, and the like, are described in U.S. patent application publication 2003/0072799 A1. Individual modules by way of which methods for producing medicine molds are capable of being carried out are disclosed in the mentioned document. In the case of the pressure frame disclosed in U.S. patent application publication 2003/072799 A1, it is disadvantageous that the guide profiles thereof are not embodied so as to be open, and that the upper and lower pressure roller receptacles are not embodied so as to be mutually adjustable.
U.S. Pat. No. 2,846,723 A describes a rotary tablet press by means of which, in particular, at least two different tableting operations can be performed, and in which more than one pair of pressure rollers is used. U.S. Pat. No. 2,846,723 A discloses an overload protection in which a spiral-shaped helical spring is used.
A press by way of which reproducible pressing and ejecting operations may be simulated is disclosed in WO 99/33624, wherein the press rams are moved by means of replaceable pressure rollers. However, in the case of the press disclosed in WO 99/33624, the pressure rollers are not present as being disposed on a common pressure roller station.
A rotary press in which two pressure rollers which enable the movement of press rams are present is disclosed in GB 842,189 A. Attaching the two pressure rollers in the context of GB 842,189 A is performed in a mutually separate manner in a lower base region, or in an upper roof region of the tablet press, respectively.
A method and a device for monitoring a brake on a spindle are disclosed in EP 1354694, wherein the spindle is driven by a motor, for example an electric motor.
A rotary press having at least one pressure roller unit which by means of a holding device is releasably fastened to a mounting device is disclosed in U.S. Pat. No. 8,550,804.